(a) State two differences between weather and climate. (b) Name the instruments used in measuring the following weather elements: (i) sunshine (ii) rainfall...

Answer Details

(a) Two differences between weather and climate

(b) Instruments used to measure the weather elements

• (i) Sunshine: the Campbell-Stokes sunshine recorder.
• (ii) Rainfall: the rain gauge.
• (iii) Cloud cover: estimated by the eye in oktas (eighths) of the sky (an instrument such as a nephoscope observes cloud movement).

(c) How wind speed is measured and recorded

• Wind speed is measured with a cup anemometer, which consists of three or four hemispherical cups mounted on horizontal arms that rotate freely on a vertical spindle.
• The wind pushes the cups round, and the rate of rotation is proportional to the wind speed.
• The rotations are transmitted to a dial or counter which is calibrated to read the speed in kilometres per hour, metres per second or knots.
• The instrument is mounted in an open, exposed place about \(10\text{ m}\) above the ground, free from obstruction.
• Readings are taken at fixed times and recorded; average and gust speeds may be logged, and on the Beaufort scale the values are expressed in numbered wind forces.